State of the Art: Quantitative Cardiac MRI in Cardiac Amyloidosis

Abstract

Cardiac amyloidosis (CA) is characterized by amyloid infiltration in the myocardial extracellular space, causing heart failure. Patients with CA are currently underdiagnosed. Cardiac involvement is significantly associated with the prognosis and treatment decision‐making for CA. Early identification and accurate stratification are the crucial first step in patient management. Comprehensive cardiac MRI‐based evaluation of the cardiac structure, function, and myocardial tissue characterization assesses cardiac involvement by tracing disease processes. Emerging quantitative tissue characterization techniques have introduced new measures that can identify early staged CA and monitor disease progression or response after treatment. Quantitative cardiac MRI is becoming an instrumental tool in understanding CA, which leads to changes in individualized patient care. This review aimed to discuss the quantitative cardiac MRI‐based assessment of CA using established and emerging techniques. Evidence Level 5 Technical Efficacy Stage 3

Cardiac Amyloidosis

“…Different patterns have been observed such as diffuse patterns that can progress from subendocardial to transmural. The circumferential subendocardial LGE has been more frequently seen in patients with AL-CM whereas the diffuse transmural LGE pattern has been more frequently associated with ATTR-CM [54]. The degree and severity of LGE is associated with increased mortality.…”

“…The degree and severity of LGE is associated with increased mortality. Native (noncontrast) T1 or T1 time is measured without contrasts and may reflect changes in tissue composition such as in intracellular or extracellular compartments affected by collagen, protein, edema, lipids, and iron content [54]. Whereas postcontrast T1 is used to calculate ECV a which is a surrogate parameter for the extracellular matrix.…”

“…Whereas postcontrast T1 is used to calculate ECV a which is a surrogate parameter for the extracellular matrix. Both, native T1 and ECV have demonstrated their usefulness as biomarkers for CA diagnosis [54]. A series from National Amyloidosis Centre in the United Kingdom followed hematologic-measured treatment response and correlated them with ECV findings.…”

Light-Chain Cardiac Amyloidosis: Cardiac Magnetic Resonance for Assessing Response to Chemotherapy

“…In patients with AL-CA, the pattern of LGE and elevation in native T1 and extracellular volume fraction (ECV) are considered biomarkers of amyloid infiltration, facilitating early disease detection [ 6 7 ]. Moreover, ECV functions as a robust predictor of mortality and adds incremental value to known prognostic factors [ 8 ]. Although echocardiography is commonly used to assess ventricular function based on volumetric measures, image quality can be highly variable among patients, and defining the endocardium on long-axis images can be challenging.…”